[PATCH 01/13] alpha: switch from DISCONTIGMEM to SPARSEMEM

Mike Rapoport
2020-10-27T11:29:43Z

Enable SPARSEMEM support on alpha and deprecate DISCONTIGMEM.

The required changes are mostly around moving duplicated definitions of
page access and address conversion macros to a common place and making sure
they are available for all memory models.

The DISCONTINGMEM support is marked as BROKEN an will be removed in a
couple of releases.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
arch/alpha/Kconfig | 8 ++++++++
arch/alpha/include/asm/mmzone.h | 14 ++------------
arch/alpha/include/asm/page.h | 7 ++++---
arch/alpha/include/asm/pgtable.h | 12 +++++-------
arch/alpha/include/asm/sparsemem.h | 18 ++++++++++++++++++
arch/alpha/kernel/setup.c | 1 +
6 files changed, 38 insertions(+), 22 deletions(-)
create mode 100644 arch/alpha/include/asm/sparsemem.h

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index d6e9fc7a7b19..aedf5c296f13 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -40,6 +40,7 @@ config ALPHA
select CPU_NO_EFFICIENT_FFS if !ALPHA_EV67
select MMU_GATHER_NO_RANGE
select SET_FS
+ select SPARSEMEM_EXTREME if SPARSEMEM
help
The Alpha is a 64-bit general-purpose processor designed and
marketed by the Digital Equipment Corporation of blessed memory,
@@ -551,12 +552,19 @@ config NR_CPUS

config ARCH_DISCONTIGMEM_ENABLE
bool "Discontiguous Memory Support"
+ depends on BROKEN
help
Say Y to support efficient handling of discontiguous physical memory,
for architectures which are either NUMA (Non-Uniform Memory Access)
or have huge holes in the physical address space for other reasons.
See <file:Documentation/vm/numa.rst> for more.

+config ARCH_SPARSEMEM_ENABLE
+ bool "Sparse Memory Support"
+ help
+ Say Y to support efficient handling of discontiguous physical memory,
+ for systems that have huge holes in the physical address space.
+
config NUMA
bool "NUMA Support (EXPERIMENTAL)"
depends on DISCONTIGMEM && BROKEN
diff --git a/arch/alpha/include/asm/mmzone.h b/arch/alpha/include/asm/mmzone.h
index 9b521c857436..86644604d977 100644
--- a/arch/alpha/include/asm/mmzone.h
+++ b/arch/alpha/include/asm/mmzone.h
@@ -6,6 +6,8 @@
#ifndef _ASM_MMZONE_H_
#define _ASM_MMZONE_H_

+#ifdef CONFIG_DISCONTIGMEM
+
#include <asm/smp.h>

/*
@@ -45,8 +47,6 @@ PLAT_NODE_DATA_LOCALNR(unsigned long p, int n)
}
#endif

-#ifdef CONFIG_DISCONTIGMEM
-
/*
* Following are macros that each numa implementation must define.
*/
@@ -68,11 +68,6 @@ PLAT_NODE_DATA_LOCALNR(unsigned long p, int n)
/* XXX: FIXME -- nyc */
#define kern_addr_valid(kaddr) (0)

-#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
-
-#define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> 32))
-#define pte_pfn(pte) (pte_val(pte) >> 32)
-
#define mk_pte(page, pgprot) \
({ \
pte_t pte; \
@@ -95,16 +90,11 @@ PLAT_NODE_DATA_LOCALNR(unsigned long p, int n)
__xx; \
})

-#define page_to_pa(page) \
- (page_to_pfn(page) << PAGE_SHIFT)
-
#define pfn_to_nid(pfn) pa_to_nid(((u64)(pfn) << PAGE_SHIFT))
#define pfn_valid(pfn) \
(((pfn) - node_start_pfn(pfn_to_nid(pfn))) < \
node_spanned_pages(pfn_to_nid(pfn))) \

-#define virt_addr_valid(kaddr) pfn_valid((__pa(kaddr) >> PAGE_SHIFT))
-
#endif /* CONFIG_DISCONTIGMEM */

#endif /* _ASM_MMZONE_H_ */
diff --git a/arch/alpha/include/asm/page.h b/arch/alpha/include/asm/page.h
index e241bd88880f..268f99b4602b 100644
--- a/arch/alpha/include/asm/page.h
+++ b/arch/alpha/include/asm/page.h
@@ -83,12 +83,13 @@ typedef struct page *pgtable_t;

#define __pa(x) ((unsigned long) (x) - PAGE_OFFSET)
#define __va(x) ((void *)((unsigned long) (x) + PAGE_OFFSET))
-#ifndef CONFIG_DISCONTIGMEM
+
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
+#define virt_addr_valid(kaddr) pfn_valid((__pa(kaddr) >> PAGE_SHIFT))

+#ifdef CONFIG_FLATMEM
#define pfn_valid(pfn) ((pfn) < max_mapnr)
-#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
-#endif /* CONFIG_DISCONTIGMEM */
+#endif /* CONFIG_FLATMEM */

#include <asm-generic/memory_model.h>
#include <asm-generic/getorder.h>
diff --git a/arch/alpha/include/asm/pgtable.h b/arch/alpha/include/asm/pgtable.h
index 660b14ce1317..8d856c62e22a 100644
--- a/arch/alpha/include/asm/pgtable.h
+++ b/arch/alpha/include/asm/pgtable.h
@@ -203,10 +203,10 @@ extern unsigned long __zero_page(void);
* Conversion functions: convert a page and protection to a page entry,
* and a page entry and page directory to the page they refer to.
*/
-#ifndef CONFIG_DISCONTIGMEM
-#define page_to_pa(page) (((page) - mem_map) << PAGE_SHIFT)
-
+#define page_to_pa(page) (page_to_pfn(page) << PAGE_SHIFT)
#define pte_pfn(pte) (pte_val(pte) >> 32)
+
+#ifndef CONFIG_DISCONTIGMEM
#define pte_page(pte) pfn_to_page(pte_pfn(pte))
#define mk_pte(page, pgprot) \
({ \
@@ -236,10 +236,8 @@ pmd_page_vaddr(pmd_t pmd)
return ((pmd_val(pmd) & _PFN_MASK) >> (32-PAGE_SHIFT)) + PAGE_OFFSET;
}

-#ifndef CONFIG_DISCONTIGMEM
-#define pmd_page(pmd) (mem_map + ((pmd_val(pmd) & _PFN_MASK) >> 32))
-#define pud_page(pud) (mem_map + ((pud_val(pud) & _PFN_MASK) >> 32))
-#endif
+#define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> 32))
+#define pud_page(pud) (pfn_to_page(pud_val(pud) >> 32))

extern inline unsigned long pud_page_vaddr(pud_t pgd)
{ return PAGE_OFFSET + ((pud_val(pgd) & _PFN_MASK) >> (32-PAGE_SHIFT)); }
diff --git a/arch/alpha/include/asm/sparsemem.h b/arch/alpha/include/asm/sparsemem.h
new file mode 100644
index 000000000000..a0820fd2d4b1
--- /dev/null
+++ b/arch/alpha/include/asm/sparsemem.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_ALPHA_SPARSEMEM_H
+#define _ASM_ALPHA_SPARSEMEM_H
+
+#ifdef CONFIG_SPARSEMEM
+
+#define SECTION_SIZE_BITS 27
+
+/*
+ * According to "Alpha Architecture Reference Manual" physical
+ * addresses are at most 48 bits.
+ * https://download.majix.org/dec/alpha_arch_ref.pdf
+ */
+#define MAX_PHYSMEM_BITS 48
+
+#endif /* CONFIG_SPARSEMEM */
+
+#endif /* _ASM_ALPHA_SPARSEMEM_H */
diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c
index 916e42d74a86..03dda3beb3bd 100644
--- a/arch/alpha/kernel/setup.c
+++ b/arch/alpha/kernel/setup.c
@@ -648,6 +648,7 @@ setup_arch(char **cmdline_p)
/* Find our memory. */
setup_memory(kernel_end);
memblock_set_bottom_up(true);
+ sparse_init();

/* First guess at cpu cache sizes. Do this before init_arch. */
determine_cpu_caches(cpu->type);
--
2.28.0